[Hypersensitivity angiitis, Henoch-Schönlein purpura].

Pathogenesis and treatment of hypersensitivity angiitis and Henoch-Schönlein purpura were summarized. Both diseases were included in the category of "leukocytoclastic vasculitis". Hypersensitivity angiitis was frequently associated with drug or infectious exposure and the involvement of venules and capillaries. Many patients with this disease have detectable autoantibodies to neutrophil cytoplasmic antigens (ANCA) typically reactive with myeloperoxidase. Henoch-Schönlein purpura was characterized by vasculitis in multiple organs such as the skin, joints, gastrointestinal tract and kidneys. Henoch-Schönlein purpura nephritis revealed marked deposition of IgA (mainly IgA1) and C3 in the glomerular mesangial areas and capillary walls by immunofluorescence. Combinations of intensive plasma exchange, steroids and cyclophosphamide were effective for patients with both diseases.